A conventional louver consists of louver blades with arch-up cross sections, halyards, ladder tapes, a top rail and a base tail. A rotary actuator with self-locking function, a rotating shaft, several winding halyards and rollers for controlling the ladder tapes are installed in the top rail, the rotating shaft passes through the rotary actuator and the roller, there are ladder tapes between the top rail and the base rail, the lower ends of the ladder tapes are in fixed connection with the base rail, and two upper ends of the ladder tapes are butted and sheathed on the roller; a plurality of louver blades in parallel are put in the breast line of the ladder tape, a through hole is set at a symmetric center of the cross section of the louver blade to allow the halyard to pass through, the lower end of the halyard is in fixed connection with the base rail, and the upper end of the halyard is wound on the roller; the rotating shaft and the roller are driven to rotate by the rotary actuator, thus the louver blades can be lifted and turned; when the louver blades are folded, the halyards are wound to drive the base rail to rise, thus sequentially lifting up and folding the louver blades, and when the louver blades are unfolded, the halyards are unwound, and under the gravity of the base rail, the louver blades move down sequentially and are placed at an equal distance separated by the breast line of the ladder tape; when the base rail reaches the windowsill, the halyards are unwound completely, and when the rotary actuator continues to be pulled, the roller rotating together with the rotating shaft will turn the louver blades over under the action of frictional force, thus achieving the effect of adjusting indoor light. In practice, the roller for winding the halyards can also be replaced by a screw (see Utility Model ZL 02201583.3, Utility Model ZL 200420078400.6 and Patent Application No. 200480014523.6), and the roller which drives the ladder tapes to rotate by virtue of frictional force or bayonet can also be replaced by a torsion spring or a snap spring wheel (see Patent Application No. 200480014523.6).
One of critical defects of the conventional louver is that indoor daylight illumination could not be uniform. If the louver blades are turned and adjusted until the light near the window is moderate and glareless, the light deep into the interior is not enough, and it requires artificial lighting. If the louver blades are turned and adjusted until the light deep into the interior is moderate, the light near the window is glare. In addition, people only need moderate light, but no heat in summer, and people need both moderate light and heat in winter, however, for the purpose of reducing light and heat near the window, the louver blades of the conventional louver must be turned to the extent that the louver are almost closed whether in summer or in winter, which results in that the whole room is too dark, and appropriate indoor illumination should be maintained by artificial lighting whether in sunny day or cloudy day, thus causing enormous energy wastage and also reducing people's comfort and work efficiency. Therefore, in order to prevent glare and overheating near the window and give uniform daylight illumination deep into the interior, Chinese Patent Application (Application No. 201010162501.1 and Application No. 2010 1062 0508.3) discloses two combinatorial louver blades which can change space between louver blades, a combinatorial louver composed of such combinatorial louver blades would not change the path of light irradiating to the louver blades no matter whether the sun altitude H is greater or less than the shading angle of the louver, thus it can not only meet the requirement for preventing glare and overheating near the window, but also meet the requirement for uniform daylight illumination deep into the interior. Meanwhile, visual communication and air flow indoor and outdoor will not be affected. However, this patent application only disclosed the combinatorial structure of the combinatorial louver blades as well as shading and light guiding effects of relatively lifting and turning over the louver blade, and did not disclose a driving mechanism associated with such combinatorial louver. The invention discloses a roller system for the above-mentioned louver. This roller system is also applicable to a new scheme-a pitch-variable combinatorial louver with more than three secondary louver blades, which is extended from the above inventions (201010162501.1 and 2010 1062 0508.3).
The pitch D referred to in the invention is the distance between two adjacent primary louver blades, the width L of the louver blade is the horizontal width of the cross section of the louver blade, the pitch ratio D/L is the ratio of the pitch D to the width L of the louver blade, the pitch ratio D/L is the ratio of the louver pitch D to the width L of the louver blade, D1 is the vertical distance of a first secondary louver blade relative to a lower primary louver blade of two adjacent primary louver blades, D2 is the vertical distance of a second secondary louver blade relative to a lower primary louver blade of two adjacent primary louver blades, D3 is the vertical distance of a third secondary louver blade relative to a lower primary louver blade of two adjacent primary louver blades, and φ is an angle that the louver blade is turned from a horizontal position to a closed position.